Hello, and thank you for your interest in the EMS! The audio messages are just acknowledging that there is no audio (AUNK = audio unknown). The lack of audio will not affect the processing of the video portion of the stream. There are a couple of known-issues with EMS version 1.6.3 supporting RTSP security cameras. In the last few months we have worked with several customers to significantly improve the robustness of RTSP camera support. We will be releasing a new version of the EMS (1.6.4) either tomorrow or Monday. In the mean-time you can also update your release to our most recent Release Candidate, which can be found here:
http://tarballs.evostream.com/release/2514/
Your current license, and the installation of the EMS Web UI will both work fine with this new EMS version.
Bryan